In this continuation application, the investigators plan to conduct three studies that include neuropsychological and psychosocial assessments, as well as physical examinations and laboratory measures. The first is a prospective study that tests the hypothesis that the subsequent occurrence (or worsening) of certain biomedical complications will be associated with the development of mild neuropsychological dysfunction. To that end, subjects will be re-evaluated 6 years after their initial assessment when many of them will have developed their first clinically significant biomedical complications, or a worsening of earlier complications. The second study is cross-sectional and is designed to develop a model that explains the complex interactions among microvascular complications, normal aging and its illnesses, chronic hyperglycemia, and neuropsychological processes. To that end, the investigator will recruit from the community groups of younger and older Type 1 diabetic subjects, including those with significant microvascular disease. A major goal of the third study is to determine the etiology for memory disorders in diabetic adults. The investigators have hypothesized that the memory disorders commonly seen in elderly Type 2 diabetic adults (but rarely reported in younger Type 1 diabetic adults) reflect an interaction between chronic hyperglycemia and aging. A group of younger and older Type 2 diabetic adults will be recruited and compare their memory skills will be compared to younger and older Type 1 diabetic adults recruited from the community.